<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .container{
            display: flex;
            max-width: 1200px;
            margin: 0 auto;
            /* 两端对齐 */
            justify-content: space-between;
            /* 居中对齐 */
            /* align-items: center; */
            /* 换行 */
            flex-wrap: wrap;
            /* 项目对齐 */
            /* align-content: center; */
            /* 项目间距 */
            gap: 50px;
        }
        .item{
            width: 100px;
            height: 100px;
            line-height: 100px;
            text-align: center;
            background-color: pink;
            margin-top: 50px;
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="item">1</div>
        <div class="item">2</div>
        <div class="item">3</div>
    </div>
</body>
</html>